package com.csaba.swing.gui.util;

import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;

import javax.swing.Icon;
import javax.swing.JLabel;
import javax.swing.JTable;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.JTableHeader;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumnModel;
import javax.swing.table.TableModel;

/**
 * TableSorter is a decorator for TableModels; adding sorting functionality to a
 * supplied TableModel. TableSorter does not store or copy the data in its
 * TableModel; instead it maintains a map from the row indexes of the view to
 * the row indexes of the model. As requests are made of the sorter (like
 * getValueAt(row, col)) they are passed to the underlying model after the row
 * numbers have been translated via the internal mapping array. This way, the
 * TableSorter appears to hold another copy of the table with the rows in a
 * different order. <p/>TableSorter registers itself as a listener to the
 * underlying model, just as the JTable itself would. Events recieved from the
 * model are examined, sometimes manipulated (typically widened), and then
 * passed on to the TableSorter's listeners (typically the JTable). If a change
 * to the model has invalidated the order of TableSorter's rows, a note of this
 * is made and the sorter will resort the rows the next time a value is
 * requested. <p/>When the tableHeader property is set, either by using the
 * setTableHeader() method or the two argument constructor, the table header may
 * be used as a complete UI for TableSorter. The default renderer of the
 * tableHeader is decorated with a renderer that indicates the sorting status of
 * each column. In addition, a mouse listener is installed with the following
 * behavior:
 * <ul>
 * <li>Mouse-click: Clears the sorting status of all other columns and advances
 * the sorting status of that column through three values: {NOT_SORTED,
 * ASCENDING, DESCENDING} (then back to NOT_SORTED again).
 * <li>SHIFT-mouse-click: Clears the sorting status of all other columns and
 * cycles the sorting status of the column through the same three values, in the
 * opposite order: {NOT_SORTED, DESCENDING, ASCENDING}.
 * <li>CONTROL-mouse-click and CONTROL-SHIFT-mouse-click: as above except that
 * the changes to the column do not cancel the statuses of columns that are
 * already sorting - giving a way to initiate a compound sort.
 * </ul>
 * <p/>This is a long overdue rewrite of a class of the same name that first
 * appeared in the swing table demos in 1997.
 * 
 * @author Philip Milne
 * @author Brendon McLean
 * @author Dan van Enckevort
 * @author Parwinder Sekhon
 * @version 2.0 02/27/04
 */

@SuppressWarnings( "serial" )
public class TableSorter extends AbstractTableModel
{
	public static final int DESCENDING = -1;
	public static final int NOT_SORTED = 0;
	public static final int ASCENDING = 1;

	protected TableModel tableModel;

	private static Directive EMPTY_DIRECTIVE = new Directive(-1, NOT_SORTED);

	@SuppressWarnings( "unchecked" )
	public static final Comparator<Comparable> COMPARABLE_COMPARATOR = new Comparator<Comparable>()
	{

		public int compare( final Comparable o1, final Comparable o2 )
		{
			return o1.compareTo(o2);
		}
	};

	@SuppressWarnings( "unchecked" )
	public static final Comparator LEXICAL_COMPARATOR = new Comparator()
	{

		public int compare( final Object o1, final Object o2 )
		{
			return o1.toString().compareTo(o2.toString());
		}
	};

	private Row[] viewToModel;

	private int[] modelToView;

	private JTableHeader tableHeader;

	private final MouseListener mouseListener;

	private final TableModelListener tableModelListener;

	private final HashMap<Class<?>, Comparator<?>> columnComparators = new HashMap<Class<?>, Comparator<?>>();

	private final List<Directive> sortingColumns = new ArrayList<Directive>();

	public TableSorter()
	{
		this.mouseListener = new MouseHandler();
		this.tableModelListener = new TableModelHandler();
	}

	public TableSorter( final TableModel tableModel )
	{
		this();
		setTableModel(tableModel);
	}

	public TableSorter( final TableModel tableModel, final JTableHeader tableHeader )
	{
		this();
		setTableHeader(tableHeader);
		setTableModel(tableModel);
	}

	private void clearSortingState()
	{
		viewToModel = null;
		modelToView = null;
	}

	public TableModel getTableModel()
	{
		return tableModel;
	}

	public void setTableModel( final TableModel tableModel )
	{
		if ( this.tableModel != null )
		{
			this.tableModel.removeTableModelListener(tableModelListener);
		}

		this.tableModel = tableModel;
		if ( this.tableModel != null )
		{
			this.tableModel.addTableModelListener(tableModelListener);
		}

		clearSortingState();
		fireTableStructureChanged();
	}

	public JTableHeader getTableHeader()
	{
		return tableHeader;
	}

	public void setTableHeader( final JTableHeader tableHeader )
	{
		if ( this.tableHeader != null )
		{
			this.tableHeader.removeMouseListener(mouseListener);
			final TableCellRenderer defaultRenderer = this.tableHeader.getDefaultRenderer();
			if ( defaultRenderer instanceof SortableHeaderRenderer )
			{
				this.tableHeader.setDefaultRenderer(( (SortableHeaderRenderer) defaultRenderer ).tableCellRenderer);
			}
		}
		this.tableHeader = tableHeader;
		if ( this.tableHeader != null )
		{
			this.tableHeader.addMouseListener(mouseListener);
			this.tableHeader.setDefaultRenderer(new SortableHeaderRenderer(this.tableHeader.getDefaultRenderer()));
		}
	}

	public boolean isSorting()
	{
		return sortingColumns.size() != 0;
	}

	private Directive getDirective( final int column )
	{
		for ( int i = 0; i < sortingColumns.size(); i++ )
		{
			final Directive directive = sortingColumns.get(i);
			if ( directive.column == column )
			{
				return directive;
			}
		}
		return EMPTY_DIRECTIVE;
	}

	public int getSortingStatus( final int column )
	{
		return getDirective(column).direction;
	}

	private void sortingStatusChanged()
	{
		clearSortingState();
		fireTableDataChanged();
		if ( tableHeader != null )
		{
			tableHeader.repaint();
		}
	}

	public void setSortingStatus( final int column, final int status )
	{
		final Directive directive = getDirective(column);
		if ( directive != EMPTY_DIRECTIVE )
		{
			sortingColumns.remove(directive);
		}
		if ( status != NOT_SORTED )
		{
			sortingColumns.add(new Directive(column, status));
		}
		sortingStatusChanged();
	}

	protected Icon getHeaderRendererIcon( final int column, final int size )
	{
		final Directive directive = getDirective(column);
		if ( directive == EMPTY_DIRECTIVE )
		{
			return null;
		}
		return new Arrow(directive.direction == DESCENDING, size, sortingColumns.indexOf(directive));
	}

	private void cancelSorting()
	{
		sortingColumns.clear();
		sortingStatusChanged();
	}

	public void setColumnComparator( final Class<?> type, final Comparator<?> comparator )
	{
		if ( comparator == null )
		{
			columnComparators.remove(type);
		}
		else
		{
			columnComparators.put(type, comparator);
		}
	}

	@SuppressWarnings( "unchecked" )
	protected Comparator getComparator( final int column )
	{
		final Class<?> columnType = tableModel.getColumnClass(column);
		final Comparator<?> comparator = columnComparators.get(columnType);
		if ( comparator != null )
		{
			return comparator;
		}
		if ( Comparable.class.isAssignableFrom(columnType) )
		{
			return COMPARABLE_COMPARATOR;
		}
		return LEXICAL_COMPARATOR;
	}

	private Row[] getViewToModel()
	{
		if ( viewToModel == null )
		{
			final int tableModelRowCount = tableModel.getRowCount();
			viewToModel = new Row[tableModelRowCount];
			for ( int row = 0; row < tableModelRowCount; row++ )
			{
				viewToModel[row] = new Row(row);
			}

			if ( isSorting() )
			{
				Arrays.sort(viewToModel);
			}
		}
		return viewToModel;
	}

	public int modelIndex( final int viewIndex )
	{
		return getViewToModel()[viewIndex].modelIndex;
	}

	private int[] getModelToView()
	{
		if ( modelToView == null )
		{
			final int n = getViewToModel().length;
			modelToView = new int[n];
			for ( int i = 0; i < n; i++ )
			{
				modelToView[modelIndex(i)] = i;
			}
		}
		return modelToView;
	}

	// TableModel interface methods

	public int getRowCount()
	{
		return ( tableModel == null ) ? 0 : tableModel.getRowCount();
	}

	public int getColumnCount()
	{
		return ( tableModel == null ) ? 0 : tableModel.getColumnCount();
	}

	@Override
	public String getColumnName( final int column )
	{
		return tableModel.getColumnName(column);
	}

	@Override
	public Class<?> getColumnClass( final int column )
	{
		return tableModel.getColumnClass(column);
	}

	@Override
	public boolean isCellEditable( final int row, final int column )
	{
		return tableModel.isCellEditable(modelIndex(row), column);
	}

	public Object getValueAt( final int row, final int column )
	{
		return tableModel.getValueAt(modelIndex(row), column);
	}

	@Override
	public void setValueAt( final Object aValue, final int row, final int column )
	{
		tableModel.setValueAt(aValue, modelIndex(row), column);
	}

	// Helper classes

	private class Row implements Comparable<Row>
	{

		private final int modelIndex;

		public Row( final int index )
		{
			this.modelIndex = index;
		}

		@SuppressWarnings( "unchecked" )
		public int compareTo( final Row o )
		{
			final int row1 = modelIndex;
			final int row2 = ( o ).modelIndex;

			for ( final Directive directive : sortingColumns )
			{
				final int column = directive.column;
				final Object o1 = tableModel.getValueAt(row1, column);
				final Object o2 = tableModel.getValueAt(row2, column);

				int comparison = 0;
				// Define null less than everything, except null.
				if ( o1 == null && o2 == null )
				{
					comparison = 0;
				}
				else if ( o1 == null )
				{
					comparison = -1;
				}
				else if ( o2 == null )
				{
					comparison = 1;
				}
				else
				{
					comparison = getComparator(column).compare(o1, o2);
				}
				if ( comparison != 0 )
				{
					return directive.direction == DESCENDING ? -comparison : comparison;
				}
			}
			return 0;
		}
	}

	private class TableModelHandler implements TableModelListener
	{

		public void tableChanged( final TableModelEvent e )
		{
			// If we're not sorting by anything, just pass the event along.
			if ( !isSorting() )
			{
				clearSortingState();
				fireTableChanged(e);
				return;
			}

			// If the table structure has changed, cancel the sorting; the
			// sorting columns may have been either moved or deleted from
			// the model.
			if ( e.getFirstRow() == TableModelEvent.HEADER_ROW )
			{
				cancelSorting();
				fireTableChanged(e);
				return;
			}

			// We can map a cell event through to the view without widening
			// when the following conditions apply:
			// 
			// a) all the changes are on one row (e.getFirstRow() ==
			// e.getLastRow()) and,
			// b) all the changes are in one column (column !=
			// TableModelEvent.ALL_COLUMNS) and,
			// c) we are not sorting on that column (getSortingStatus(column) ==
			// NOT_SORTED) and,
			// d) a reverse lookup will not trigger a sort (modelToView != null)
			//
			// Note: INSERT and DELETE events fail this test as they have column
			// == ALL_COLUMNS.
			// 
			// The last check, for (modelToView != null) is to see if
			// modelToView
			// is already allocated. If we don't do this check; sorting can
			// become
			// a performance bottleneck for applications where cells
			// change rapidly in different parts of the table. If cells
			// change alternately in the sorting column and then outside of
			// it this class can end up re-sorting on alternate cell updates -
			// which can be a performance problem for large tables. The last
			// clause avoids this problem.
			final int column = e.getColumn();
			if ( e.getFirstRow() == e.getLastRow() && column != TableModelEvent.ALL_COLUMNS
					&& getSortingStatus(column) == NOT_SORTED && modelToView != null )
			{
				final int viewIndex = getModelToView()[e.getFirstRow()];
				fireTableChanged(new TableModelEvent(TableSorter.this, viewIndex, viewIndex, column, e.getType()));
				return;
			}

			// Something has happened to the data that may have invalidated the
			// row order.
			clearSortingState();
			fireTableDataChanged();
			return;
		}
	}

	private class MouseHandler extends MouseAdapter
	{

		@Override
		public void mouseClicked( final MouseEvent e )
		{
			final JTableHeader h = (JTableHeader) e.getSource();
			final TableColumnModel columnModel = h.getColumnModel();
			final int viewColumn = columnModel.getColumnIndexAtX(e.getX());
			final int column = columnModel.getColumn(viewColumn).getModelIndex();
			if ( column != -1 )
			{
				int status = getSortingStatus(column);
				if ( !e.isControlDown() )
				{
					cancelSorting();
				}
				// Cycle the sorting states through {NOT_SORTED, ASCENDING,
				// DESCENDING} or
				// {NOT_SORTED, DESCENDING, ASCENDING} depending on whether
				// shift is pressed.
				status = status + ( e.isShiftDown() ? -1 : 1 );
				status = ( status + 4 ) % 3 - 1; // signed mod, returning {-1,
				// 0, 1}
				setSortingStatus(column, status);
			}
		}
	}

	private static class Arrow implements Icon
	{

		private final boolean descending;

		private final int size;

		private final int priority;

		public Arrow( final boolean descending, final int size, final int priority )
		{
			this.descending = descending;
			this.size = size;
			this.priority = priority;
		}

		public void paintIcon( final Component c, final Graphics g, final int x, int y )
		{
			final Color color = c == null ? Color.GRAY : c.getBackground();
			// In a compound sort, make each succesive triangle 20%
			// smaller than the previous one.
			final int dx = (int) ( size / 2 * Math.pow(0.8, priority) );
			final int dy = descending ? dx : -dx;
			// Align icon (roughly) with font baseline.
			y = y + 5 * size / 6 + ( descending ? -dy : 0 );
			final int shift = descending ? 1 : -1;
			g.translate(x, y);

			// Right diagonal.
			g.setColor(color.darker());
			g.drawLine(dx / 2, dy, 0, 0);
			g.drawLine(dx / 2, dy + shift, 0, shift);

			// Left diagonal.
			g.setColor(color.brighter());
			g.drawLine(dx / 2, dy, dx, 0);
			g.drawLine(dx / 2, dy + shift, dx, shift);

			// Horizontal line.
			if ( descending )
			{
				g.setColor(color.darker().darker());
			}
			else
			{
				g.setColor(color.brighter().brighter());
			}
			g.drawLine(dx, 0, 0, 0);

			g.setColor(color);
			g.translate(-x, -y);
		}

		public int getIconWidth()
		{
			return size;
		}

		public int getIconHeight()
		{
			return size;
		}
	}

	private class SortableHeaderRenderer implements TableCellRenderer
	{

		private final TableCellRenderer tableCellRenderer;

		public SortableHeaderRenderer( final TableCellRenderer tableCellRenderer )
		{
			this.tableCellRenderer = tableCellRenderer;
		}

		public Component getTableCellRendererComponent( final JTable table, final Object value,
				final boolean isSelected, final boolean hasFocus, final int row, final int column )
		{
			final Component c = tableCellRenderer.getTableCellRendererComponent(table, value, isSelected, hasFocus,
					row, column);
			if ( c instanceof JLabel )
			{
				final JLabel l = (JLabel) c;
				l.setHorizontalTextPosition(JLabel.LEFT);
				final int modelColumn = table.convertColumnIndexToModel(column);
				l.setIcon(getHeaderRendererIcon(modelColumn, l.getFont().getSize()));
			}
			return c;
		}
	}

	private static class Directive
	{

		private final int column;

		private final int direction;

		public Directive( final int column, final int direction )
		{
			this.column = column;
			this.direction = direction;
		}
	}
}